Cd污染农田的炭基修复方案设计和效果评价

为了解不同Cd污染农田土壤上炭基改良剂的治理效果，运用土壤医生理念，针对广东省韶关和云浮3个重金属Cd污染状况和土壤理化性质不同的区域农田分别设计了3种以生物炭为主要原料，搭配石灰、有机肥等不同辅料的3种生物炭基土壤改良剂，并进行了大田应用试验，同时归纳总结设计原则，评价设计的3种改良剂对Cd污染农田的治理效果。结果表明：在3个区域施用的改良剂均不会降低作物的产量，在Cd污染严重的酸性土壤上有显著增产的效果（增产效果达到383.03%）；同时施加3种不同配方的炭基改良剂均可以有效降低作物可食用部位的Cd含量，分别是对照的33.33%、46.88%和42.86%，使3个试验区的农产品可食用部分Cd含量均达到国家标准；施用炭基改良剂，可有效降低土壤中酸溶态Cd的含量，尤其是在酸性较强、Cd污染程度高的土壤中，能够将土壤中活性和生物可利用形态的Cd含量降低18.28%。综上所述，根据土壤理化性质、污染程度和修复目的来针对性设计以生物炭为基础的炭基改良剂可以保障作物产量，提高作物品质，实现对南方Cd污染土壤的改良。

Evaluating the effects of specifically designed biochar amendments on the remediation of cadmiumcontaminated soils

Three biochar-based treatments were designed and tested in three demonstration plots(two plots in Shaoguan and one plot in Yunfu), containing different levels of Cd and varying physical/chemical properties, to evaluate the effects of biochar treatment on cadmium-polluted soils. The results showed that the application of the designed biochar-based treatment did not reduce crop yield in any of the three plots. In fact, maize yield significantly increased by 383.03% in heavily Cd-contaminated soils. Compared to the control treatment, the designed biochar-based treatments led to decreases in the Cd content of edible plant parts by 33.33%(maize grain), 46.88%(brown rice) and 42.86%(brown rice), respectively. Meanwhile, the treatment of areas 1 and 2 resulted in the Cd content of the agricultural products to meet Chinese health standards. The application of biochar-based treatments could reduce the content of acid-soluble Cd in soils, particularly in strongly acidic and highly Cd-polluted soils, as in area 1. The B1 treatment could reduce the bioavailable Cd content of soils by 81.72%. Overall, designing biochar-based treatments based on degree of soil heavy metal pollution and soil physical/chemical properties maintained crop yields, reduced the Cd content of edible plant parts, and remediated soils contaminated with heavy metals in southern China.